1. Field of the Invention
This invention relates to well tools and more particularly to flow controlling devices, especially devices for controlling injection of treating fluids and kill fluids in wells.
2. Description of the Prior Art
Chemical injection valves have been used for many years in wells for controlling injection of treating fluids into well tubing at subsurface levels, for instance, for purposes of controlling corrosion, deposition of paraffin, and the like. Such valves are generally installed in and removed from receptacles, which form a part of the tubing, through use of wireline equipment and techniques or by through flow line (TFL) methods commonly called "pumpdown" so that such valves can be readily repaired or replaced without removing the tubing from the well.
Also, circulation valves have been used in wells for many years. The tools generally have an openable passage which permits the well to be "killed" or loaded with fluid when necessary.
Further, it is common practice to place such valves in a side pocket mandrel in which an offset receptacle is provided. Thus, such valves do not obstruct flow through the tubing. In addition, other well tools can be moved past them and any one of such valves or other devices can be serviced without disturbing other tools in the tubing.
It is sometimes desirable to inject chemicals or other treating fluids at a very low rate into the tubing of a well through use of a subsurface injection valve during the production phase. Then when it is desired to load the well with kill fluid, it becomes desirable to inject such fluid at a very much higher rate. Since chemical injection valves are designed for very low flow rates, it is very difficult, slow, and costly to kill a well by injecting fluids therethrough.
Examples of chemical injection valves and circulation tools are found in the following U.S. Pat. Nos.:
2,606,616; PA1 2,726,723; PA1 2,962,097; PA1 3,051,243; PA1 3,211,232; PA1 3,871,450; PA1 3,993,129; PA1 4,039,031.
U.S. Pat. No. 3,871,450 issued to Marion B. Jett, et al. on Mar. 18, 1975 for "DUAL STRING CIRCULATING VALVE." This patent shows a sleeve having a pair of bores in which is received a pair of tubular sections forming portions of a pair of tubing strings in a well. This sleeve is initially releasably secured in position covering a circulation port in one of the tubular sections. A second sleeve surrounds the other tubular section and covers a lateral port therein. Pressuring up said one tubular section will lift both sleeves and uncover the circulation ports to permit killing the well by circulating of weighted fluids into it. Pressuring up said other tubular section forces both of the sleeves down to a level below the initial level. In this lowermost position, a pair of o-rings of equal size straddle the circulation ports, in which position the sleeve is latched and cannot be displaced therefrom.
U.S. Pat. No. 4,039,032 issued to Talmadge L. Crowe on Aug. 3, 1977 for "WELL CONTROL VALVE APPARATUS." This patent shows a flow control device for use in the offset receptacle of a side pocket mandrel in a well. It has a body with a flow passage therethrough having one end thereof in communication with the exterior of the tubing and with the other end thereof in communication with the interior of the tubing. Intermediate its ends, there is a rupturable disc sealing the flow passage, and below this, there is a plug sealingly engaged in the flow passage and a flange thereon is engaged with a shoulder in the passage. The plug protects the disc against rupture by pressure applied thereto through the tubing while overpressuring exterior of the tubing will rupture the disc and expel the plug, thus opening the passage for circulation of killing fluids therethrough.
U.S. Pat. No. 2,726,723 issued Dec. 13, 1955 to Lowell M. Wilhoit et al. discloses a chemical injection valve for controlling the entry of treating fluids into the well tubing from the annulus exterior thereof. This valve is installable and removable in the bypass landing nipple shown by well-known wireline methods. Since it occupies the tubing bore, other tools cannot be lowered beyond the landing nipple without first retrieving the chemical injector.
U.S. Pat. No. 2,606,616 issued to Herbert C. Otis on Aug. 12, 1952 and shows a landing nipple forming a part of a tubing string. The nipple has lateral ports and a removable sleeve covers and seals these ports. When the sleeve is removed, flow through the ports can be had for such purposes as circulating treating fluids, etc.
U.S. Pat. No. 3,051,243 issued to George G. Grimmer et al. on Aug. 28, 1962 and discloses a sliding sleeve valve device much like that of Dollison U.S. Pat. No. 2,962,097, supra, but also shows a device for shifting the sleeve.
U.S. Pat. No. 3,211,232 which issued to George G. Grimmer on Oct. 12, 1965 discloses means utilizing pressure applied to the tubing from the surface to expel plugs from the nipple ports to permit circulation of fluids through the ports Afterwards, a ball, or the like, is dropped into the tubing and allowed to settle on expendable shifting means. Pressure then applied above the ball forces the sleeve valve to closed position and the ball and shifter are expended. Any subsequent shifting of the sleeve valve is accomplished in the conventional manner using the device of Grimmer, et al., supra, or the equivalent thereof.
U.S. Pat. No. 2,962,097 issued Nov. 29, 1960 to William W. Dollison and shows a ported nipple for use in well tubing and has a sleeve therein which is shiftable by suitable tools between port-opening and port-closing positions to permit or prevent flow through the ports.
U.S. Pat. No. 3,993,129 which issued to Fred E. Watkins on Nov. 23, 1976 discloses a "FLUID INJECTION VALVE FOR WELLS" which is suitable for use in a side pocket mandrel in a well to control injection of chemicals and other treating fluids into the tubing from the surrounding annulus. Fluids enter the side of this valve, advance to an upwardly opening passage terminating in a valve seat and there acts on the spring biased valve. The fluids lift the valve to exit the seat, then turn and flow back down through an offset passage into the lower portion of the device and out the lower end thereof into the tubing. This is similar to the injection valve mechanism of the present invention.
None of the prior art of which the applicants are aware shows a fluid injection valve for use in a side pocket mandrel in a well to control the flow of fluids from the exterior to the interior of the tubing and having a bypass passage for bypassing the valve mechanism when necessary to circulate large volumes of liquids, the bypass passage being initially closed but being openable in response to the pressure interior of the tubing exceeding that exterior thereof by a predetermined amount.